Composite plate

ABSTRACT

A protective sole plate for protective footwear having a number of sole plate bodies, optionally of an electrically and thermally insulating material, joined together with transverse hinged joint(s) whereby each sole plate body can rotate about the transverse hinge relative to other sole plate bodies thereby enabling flexing of the sole plate while maintaining puncture resistance.

FIELD OF THE INVENTION

The present invention relates to an inner sole for protective shoes,which is made of rigid plastic bodies hinged together to provideflexing, is penetration resistant, thermally insulating and electricallyinsulating.

BACKGROUND OF THE ART

Protective shoes provide foot protection for those who work in a highrisk environment. Protective shoes normally have penetration resistancein the sole and crushing resistance in the toe and metatarsal area.

Regarding the configuration of prior art protective penetrationresistant soles, conventionally a metal inner sole plate is sandwichedbetween two layers 61 of fabric material and is bonded to the shoe sole.A protective metal shoe head is positioned on the shoe sole about thetoe area. The metal inner sole plate prevents sharp tips frompenetrating and the rigid protective shoe head protects the toes frominjury from falling objects, or impact.

However, prior art protective soles have shortcomings in use.Conventional metal sole plates are often uncomfortable since it isdifficult to fabricate metal in a pressing process with a smooth concavetop surface to match the contours of a wearer's foot. The metal soleplate must have an adequate thickness to achieve penetration resistance,which complicates fabrication into a curved shape, reduces flexibilityand thus diminishes the comfort of the shoe.

The conventional metal sole plate and metal protective shoe head cannotprovide effective electric shock resistance and thermal insulation.Therefore, conventional protective shoes are not well adapted for use inan environment where electric shock is a risk or where thermalresistance to heat and cold are required.

The shape of a conventional metal sole plate is substantially flat anddoes not include a concave upper surface to follow the shape of thewearer's foot sole. Aside from the comfort factor, the flat shaperesults in protective coverage narrower than the wearer's foot sole andthus reduces the protection from sideways penetration prevention aroundthe edges of the foot.

Conventional protective soles cannot provide an effective overall heator cold resistance because the protective sole plate and protective shoehead are of metal, which is a good thermal conductor and consequently isalso a poor thermal insulator. Protective shoes are worn outdoors inconstruction or military environments and worn indoors in variousindustrial premises where the comfort of the wearer while exposed toheat and cold environments are a concern.

DISCLOSURE OF THE INVENTION

The invention provides a protective sole plate for protective footwearhaving a plurality of sole plate bodies, optionally of an electricallyand thermally insulating material, joined together with at least onetransverse hinged joint whereby each sole plate body can rotate aboutthe transverse hinge relative to other sole plate bodies, each bodyincluding at least one transverse edge adapted for hinged interactionwith an adjacent transverse edge of an adjacent sole plate body.

Objects of the invention will be apparent from review of the disclosure,drawings and description of the invention below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a rigid hinged inner soleplate according to one embodiment of the present invention;

FIG. 2 is a longitudinal cross-sectional view of a protective shoe withthe sole plate of FIG. 1 installed together with a protective toe cap;

FIG. 3 is a top plan view of the rigid sole plate of FIG. 1;

FIG. 4 is a bottom plan view of the rigid sole plate;

FIG. 5 is a cross-sectional view, taken along line 5-5 of FIG. 3;

FIG. 6 is a cross-sectional view, taken along line 6-6 of FIG. 3;

FIG. 7 is a detail sectional view, of the hinged joint in FIG. 5;

FIG. 8 is a sectional view through a protective show with the sole plateof the present invention under a bending condition in use;

FIG. 9 is a schematic cross-sectional view of the prior art one-pieceprotective sole; and

FIG. 10 is a schematic exploded perspective view of a prior artprotective shoe.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to FIGS. 9 and 10, which illustrate a configuration of theconventional shoes, a shoe sole 60 is topped with a conventional metalinner sole plate 70, which is bonded together therewith. The metal innersole plate 70 itself is sandwiched between two layers 61 of material, inorder to obtain a better combination. A protective shoe head 71, whichis made of metal material, is positioned on the shoe sole 60 at alocation corresponding to the wearer's toes.

Thus, the wearer's foot sole is protected by the inner sole plate 70.The metal inner sole plate 70 prevents sharp tips of an object frompenetrating therethrough to injure the wearer's foot sole when thewearer's foot accidentally steps on the sharp tips of the object. Therigid protective shoe head 71 protects the vulnerable toes from beinginjured even when a heavy object falls thereon.

Referring to FIGS. 1-7, the present invention relates to an improvementof an inner sole configuration for protective shoes in which a rigidplastic inner sole plate 1 is bonded to a rubber shoe sole 50. A layer51 of a material is bonded to each of the top and bottom surfaces of therigid plastic inner sole plate 1. A protective shoe head 40 (as shown inFIG. 2) is affixed to the shoe sole 50 in a position covering thewearer's toes.

In this configuration the rigid plastic inner sole plate 1 and the shoehead 40 are made of thermosetting resin with reinforcing fibers. Theshoe head 40 however can also be of metal. The rigid plastic inner soleplate 1 is configured with first, second and third plate bodies 10, 20and 30 positioned in a longitudinal sequence in correspondence with thepositions of bendable portions of the wearer's foot sole where the footjoints are located. The plate 1 includes a top surface with a concavity100 (as shown in FIG. 6) according to bioengineering, thereby beingadapted for supporting the wearer's foot sole. The plate 1 includes abottom surface having a curved configuration 101 at the peripherythereof.

The first plate body 10 includes a transverse edge 11 at an end thereofadjacent to second plate body 20 and forming a transverse hinged jointtherewith. The transverse edge 11 has at an upper part thereof a recess110 extending laterally therethrough and defines at a lower part thereofa rounded extending flange 111 (as best shown in FIG. 5).

The second plate body 20 includes a transverse edge 21 at a first endthereof adjacent to the first plate body 10. The transverse edge 21 hasan extending flange 210 extending from an upper part thereof. The flange210 is enabled to rest in the recess 110 of the first plate body 10. Aclearance is formed between an end of the recess 110 of the first platebody 10 and an end of flange 210. The transverse edge 21 furtherincludes a laterally extending rounded flange 211 (as shown in FIG. 5).The second plate body 20 includes a transverse edge 22 at a second endthereof opposite to the first end thereof. The transverse edge 22includes a recess 220 formed at an upper part and extending laterallytherethrough, and a laterally extending rounded flange 221 (as shown inFIGS. 1 and 5). An appropriate clearance is formed at each of theopposite side margins of the hinged plate 1 between a lower part of theconnecting portion 11 of the first plate body 10 and a lower part of theconnecting portion 21 of the second plate body 20. The transverse edges11 and 21 contact each other at a middle part thereof between theopposite side margins.

The third plate body 30 includes a transverse edge 31 at first endthereof toward the second plate body 20. The transverse edge 31 has aflange 310 extending from an upper part thereof to rest in the recess220 of the second plate body 20. A clearance is formed between an end ofthe recess 220 of the second plate body 20 and an end of the flange 310.An appropriate clearance is formed at each of opposite side margins ofthe plate 1 between a lower part of the transverse edge 22 of the secondplate body 20 and a lower part of the transverse edge 31 of the thirdplate body 30. The transverse edges 22 and 31 contact each other at amiddle part between the opposite side margins. Furthermore, thetransverse edge 31 includes a laterally extending rounded bottom endsurface 311 (as shown in FIG. 5 and 7). Thus, the first and second platebodies 10, 20 are enabled to bend freely and rotate relative to eachother about a transverse hinge.

The third plate body 30 further includes a recess 32 formed in a lowerpart of a second end thereof opposite to the first end thereof forengaging a rim of a rigid plastic shoe head.

In such a configuration according to the present invention, the rigidplastic inner sole plate 1 benefits from the rigidity and solidity ofthe insulating plastic material, provides an optimal overall result ofelectric shock resistance, heat resistance and thermal insulation, andthereby improves the insulation safety of the protective shoes.Additionally, the rigid plastic inner sole plate 1 provides theprotection of the wearer's foot sole from injury resulting from sharptips of an object penetrating the rubber shoe sole 50 of the protectiveshoes.

The rigid plastic inner sole plate 1 of the present invention has aconcave top surface 100 which is better fitted to the wearer's footsoles, thereby providing a better coverage and support for the wearer'sfoot soles, and thus improving the comfort of the protective shoes. Alsobecause of the concave top surface 100, the rigid plastic inner soleplate 1 extends to wrap around the opposite side areas of the wearer'sfoot soles, forming a larger coverage for the wearer's foot soles. Whena sharp tip of an object penetrates the shoe sole of the protective shoeat the side margins thereof, and then contacts the convex bottom surface101 at the periphery of the plate 1, the sharp tip will be forced andguided to project laterally and outwardly, thereby being prevented frominjuring the wearer's foot sole. Therefore, the safety of the protectiveshoes regarding lateral penetration prevention is significantlyimproved.

Furthermore, in accordance with the bendable areas of the wearer's footsole at the joints thereof, the rigid plastic inner sole plate 1 of thepresent invention includes the first, second and third plate bodies 10,20 and 30 which connect to one another at transverse hinged joints, andthe plate 1 defines an appropriate clearance respectively between thetransverse edges 11, 21 of the respective first and second plate bodies10 and 20, between the transverse edges 22, 31 of the respective secondand third plate bodies 20 and 30. Thus, the first, second and thirdplate bodies 10, 20 and 30 are freely bendable such that the respectiveplate bodies 10, 20 and 30 are hinged to bend corresponding to variousbending directions of the wearer's foot sole joints (as shown in FIG.8). The wearer's foot movement will not thus be restricted by theprotective shoe, and the wearer will thus feel much more comfortable.

Conclusively, in contrast to the soles of the conventional protectiveshoes, the improvement of the rigid plastic inner sole configuration ofthe present invention results in much better safety and comfort of theprotective shoes when in use.

1. A protective sole plate for protective footwear comprising: aplurality of sole plate bodies joined together with at least onetransverse hinged joint whereby each sole plate body can rotate aboutthe transverse hinge relative to other sole plate bodies, each bodyincluding at least one transverse edge adapted for hinged interactionwith an adjacent transverse edge of an adjacent sole plate body.
 2. Aprotective sole plate according to claim 1 comprising a first, a secondand a third sole plate body in longitudinal alignment having one saidtransverse joint between the first and the second body, and a secondsaid transverse joint between the second and the third body.
 3. Aprotective sole plate according to claim 1 wherein said transversehinged joint comprises a recess in one said transverse edge and anextending flange in the adjacent transverse edge adapted forrotationally engaging the recess.
 4. A protective sole plate accordingto claim 3 wherein the transverse hinged joint comprises: an upperflange and a lower recess in one said transverse edge, and a lowerflange and an upper recess in the adjacent transverse edge.
 5. Aprotective sole plate according to claim 3 wherein the recess and theflange have rounded engaging surfaces.
 6. A protective sole plateaccording to claim 1 wherein at least one sole plate body has a concavetop surface.
 7. A protective sole plate according to claim 1 wherein atleast one sole plate body has a convex bottom surface.
 8. A protectivesole plate according to claim 1 comprising a toe sole plate body havinga recessed toe rim in a bottom surface thereof.
 9. A protective soleplate according to claim 1 wherein said one sole plate bodies are madeof thermosetting resin.
 10. A protective sole plate according to claim 9wherein said one sole plate bodies are made of reinforcing fiberssurrounded by said thermosetting resin.